Lifting jack



.1. F. DONNELLY LIFTING JACK Filed July 19, 192'? 2 Sheets-Sheet l 3mm/1to1 cfose/eh F100/#M2554 Patented Dec. 31, 1929 JOSEPH F. DONNELLY, OF SOUTH BELLINGHAM, VASHINGTON LIFTING JACK Application led July 19,

rlhis invention relates to lifting means for el-evating any object to be raised, such as vehicle, track, machine, or other load generally lifted by means of a jack.

The invention provides an article of the nature aforesaid embodying a plurality of speeds, which are adapted to be selected according to the nature of the load, and interchangeable lift-ing heads to adaptthe jack to o special requirements.

rlVhile the drawings illustrate a preferred embodiment of the invention, it is to be understood that in adapting the means to meet specific needs and requirements, the design may be varied and such other changes in the minor details of construction may be resorted to within the scope of the invention as claimed, without departing from the spirit thereof.

For a full understanding of the invention and the merits thereof, reference is to be had to the fo-llowing description and the drawing hereto attached, in which,-

Figure 1 is a vertical, sectional view of a lifting jack embodying the invention.

Figure 2 is a plan sectional view thereof on he line 2 2 of Figure 1.

Figure 3 is a top view of the jack.

Figure 4 is a detail sectional view on the line 1 4 of Figure 1.

Figure 5 is a side view of a modified form of jack having a detachable head.

Figure 6 is a plan sectional view on the line 6-6 of Figure 5.

Figure 7 is an elevational view showing a different form of lifting head.

Corresponding and like parts are referred to in the following description and designated in the several views of the drawings by like reference characters.

rThe jack embodies a base 1, an elevating screw 2, a lifting head and a selective speed gearing, whereby the force expended may be advantageously applied according to the load to be elevated. The base 1 is hollow and contains the s-elective speed gearing.

In the form illustrated in Figure 1 and the detail views thereof, the base comprises upper and lower separable sections, and includes a standard 3 which forms a part of the upper 1927. Serial No. 206,951.

section. The standard 3 is hollow throughouti'ts lengt-h and is strengthened by external ribs 4, one of which is widened and formed with an opening to provide a handle 5. The elevating screw 2 is stepped in the bottom of 55 the base and extends through the hollow i standard 3. Guide grooves G are formed in opposite sides of the inner wall of the standard 3 and receive guide lugs 7 projecting outwardly from opposite sides of asleeve 8 60 which forms part of the lifting head. rlhe sleeve 8 is internally screw threaded to match the threads of the screw 2. A rest 9 closes the vupper end of thesleeve 8 and is formed with upwardly extending spurs to prevent slip- `G5 ping of the jack. Rotation of the elevating screw 2 effects a vertical movement of the sleeve 8 which is prevented from rotation by means of the guide lugs 7 and guide grooves 6. A worm gear 10 is fastl to the lower end 70 of the screw 2 and coacts with worm 11 of a shaft 12 which extends transversely of the base and mounted in opposite walls thereof, one end of the shaft projecting beyond the base to receive a vrench 0r other tool, where- 75 by the shaft 12 may be conveniently rotated Vfor operating the jack, either to elevate or lower the load. A gear wheel 13 fast to the shaft 12 meshes with a gear wheel 14 fast to the shaftl 15, which is mounted in a side of the base 1. An internally toothed gear wheel 1G fast to the shaft- 15 is in mesh with the gear wheel 17 fast to a shaft 1S, which is likewise mounted in a side of the base 1. The speed gearing is housed and protected by the base and any one of the speeds may be selected depending upon the load and theforce to be expended. A wrench or other operating part, not shown, is adapted to be fitted to the projecting end of any one of the shafts ac- 90 cording` to the selected speed for operating the ack. U

.ln the form of base shown in Figures 5, G and 7 the cover 19 closes the top thereof, and the elevating screw 2 obtains a bearing in tho 95 cover 19. This forni of `iack is devoid of a standard and the elevating screw projects above the top of the base, and is adapted to receive a lifting head, which may be of any determinate form, as indicated in Figures 5 100 and 7 best adapted for the particular work in hand.

The selective speed gearing comprises three shafts 12, 15 and 18, the shaft 12 being provided with the worm 11 which meshes with the worm gear 10 fast to the elevating screw 2. A gear wheel 2O fast to the shaft 12 meshes with a gear wheel 21 fast to the shaft 15. A gear wheel 22 fast to the shaft 12 meshes with a gear wheel 23 fast to the shaft 18. 1t will thus be readily understood that the elevating screw 2 may be operated at dii'erent speeds according to the load and the force to be expended. f

The lifting head shown in Figure 5 comprises a sleeve 24 and a rest 25 enclosing the upper end of the sleeve and adapted to receive the load. A handle 26 is provided at one side of the sleeve 24 for convenience of manipulating the device. The lifting head illustrated in Figure 7 comprises a sleeve 27 from which arms 28 project in opposite directions, truss braces 29 and 30 reinforcing said arms. Chains 31 depend from the outer ends of the arms 38 and are adapted to engage the rails of a railroad track for lifting the same when it is required to elevate the track.

The invention provides a lifting jack embodying selective speeds to meet varying conditions of load and power, and adapted to be readily adjusted for lifting loads requiring special appliances, the lifting heads being interchangeable for this purpose.

Having thus described the invention, I claim:

A lifting jack comprising a hollow base including upper and lower separable sections, the upper section having a hollow standard formed therewith which is strengthened by external ribs one of which forms a handle, said standard having grooves formed therein, an elevating screw mounted in the lower section and lpassing through the hollow standard, a plurality of shafts mounted between the sections of the base and geared to one another and to the elevating screw, said shafts being disposed in a horizontal plane and er; tending from one side of the base, and a sleeve threaded upon the elevating screw and freely movable within the hollow standard and having lugs connected therewith for slidably engaging said grooves to prevent rotation of the sleeve when the elevating screw is turned to raise or lower the sleeve and the load thereon. K

lIn testimony whereof Iaiiix my signature.

JOSEPH r. DONNELLY. [Le] 

